1. Field
The subject matter disclosed herein relates to electronic devices, and more particularly to methods, apparatuses and articles of manufacture for use in electronic devices that may selectively operate in different power modes.
2. Information
The Global Positioning System (GPS) and other like satellite positioning systems (SPSs) have enabled navigation services for devices in outdoor environments. Since some satellite signals may not be reliably received and/or acquired in an indoor environment, different techniques may be employed to enable position location and/or other like navigation services. In an indoor application, for example, certain devices may obtain a position fix by measuring ranges to terrestrial wireless access points (e.g., IEEE Std. 802.11 access points, etc.) that are positioned at known locations. Such ranges may be measured, for example, by obtaining a MAC ID address from signals received from such access points and measuring one or more characteristics of the received signals such as, for example, a signal strength, a round trip time (RTT) delay, a time of flight (TOF), just to name a few examples. In addition to SPSs and indoor positioning systems, existing wireless carrier infrastructures may enable observed time difference of arrival (OTDOA) and/or advanced forward link trilateration (AFLT) techniques for estimating locations of applicable devices. For example, with knowledge of the locations of neighboring base station transmitters and time-reference data, a device may estimate a range to such base station transmitters based upon an observed signal propagation delay (e.g., by comparing a phase value of an acquired signal to a time reference).
While the above identified positioning techniques have been employed by mobile handsets and other personal navigation devices, such positioning techniques may also be employed by location tracking devices such as asset tracking tags, pet collars, child tracking tags, and/or the like. Thus, for example, a location tracking device may obtain position fixes using one or more of the above techniques which may be followed by a transmission of a message to a location server (e.g., over a wireless cellular network) to report a most recent position, etc. As a location tracking device may have limited battery capacity and/or possibly a long expected deployment, it may be beneficial to conserve electrical power usage.